You may notice that your car doesn’t seem to behave the way that it used to and while the engine seems to start and run ok, your car doesn’t respond the way you expect it to or the way it did when it was new. The following symptoms are grouped into potential automatic and manual transmission issues in the way your transmission is performing. There is a separate page describing unusual transmission and drive line sounds. See Transmission Noises.
Automatic Transmissions
Transmission slippage:
If your transmission hesitates for a few seconds before engaging when you put it into Drive or Reverse, or when you step on the accelerator, it feels like your wheels are on ice because the RPM goes up but there isn’t an corresponding acceleration, your transmission may be slipping. There are a number of things that can cause this:
- Low transmission fluid can keep the torque converter from transmitting engine torque to the wheels. There must also be enough fluid to generate the pressure needed to engage the gears. See write-up on Transmission Leaks.
- Low pressure in the transmission may be a sign that the transmission filter is plugged with debris. Replacing the filter and transmission fluid can resolve this. See write-up on Transmission Fluid Replacement and Flushing.
- More severe problems may be due to a worn pump or faulty pressure regulator. These issues can often be diagnosed by connecting a monitor to your transmission control computer to read the diagnostic information that it captures. For example, it captures the engine RPM versus the transmission shaft speed to show you if the clutch is fully engaged. See the write-up on Transmission Repair.
Transmission Rough Shifts:
If the transmission doesn’t smoothly go from one gear to the next, it may be a problem with your transmission fluid levels, debris interfering with fluid solenoids, or with your car’s transmission control module. There may be information available from your car’s computer diagnostic port that can help identify the problem. Bring it in to us for free computer diagnostics and road test.
Transmission Slipping Out of Gear:
If your automatic transmission slips out of gear, get it serviced immediately. While other problems could leave you stranded by the side of the road, this one could kill you if you can’t accelerate to get out of a dangerous situation. If you think you can drive it well enough to get to our shop, we will diagnose the problem for free. If you’d rather not risk it, we will tow your car for free if you have us service your transmission failure.
Manual Transmissions
Transmission slippage:
Most often when the engine revs up but the car doesn’t accelerate correspondingly, the clutch may be slipping. This may be due to wear of the plate, a need to adjust the clutch pedal, a faulty pressure plate, or by low fluid in the master/slave cylinder.
- Clutches last 30,000 to 50,000 with city driving or more if you have more highway miles. If you “ride the clutch” … leaving it partially engaged at traffic lights or leaving your foot on it when you are driving, it will shorten the life. When it is worn, it needs to be replaced
- If the clutch pedal is not properly adjusted, when you let your foot off the pedal, the clutch may not be fully engaged
- A faulty pressure plate can prevent even pressure from being placed across the clutch disc allowing slippage
- Modern manual transmissions use hydraulics instead of cables and rods to accomplish shifting. If the fluids in your manual transmission are low, it may not operate the clutch correctly.
If you suspect a problem with your transmission, bring it in to us for free computer diagnostics and road test.
Difficulty Changing Gears:
If changing gears is difficult, the clutch may not be disengaging then engine leaving pressure on the gears when you attempt to disengage one and relying on the synchronizers to force the gear speeds to match when engaging the next. You should bring your car in for a free road test as soon as possible to assess the problem before more severe transmission damage occurs.
Transmission Slipping Out of Gear:
If your automatic transmission slips out of gear, get it serviced immediately. This could be a broken gear linkage or worn synchronizer. While other problems could leave you stranded by the side of the road, this one could kill you if you can’t accelerate to get out of a dangerous situation. If you think you can drive it well enough to get to our shop, we will diagnose the problem for free. If you’d rather not risk it, we will tow your car for free if you have us service your transmission failure.